#parmelia

Parmelia discordans

Lichens like to fuck with me. OK not just me, but lichenologists, taxonomists, naturalists, etc. They reject our attempts to classify them in any way that matters to us. Take P. discordans, which is visually very similar to P. omphalodes, but differs in its chemical composition, one of the key traits used to distinguish lichens from one another. However, recent genetic analysis has nested P. discrodans within the P. omphalodes group genetically. So is it worth describing these lichens as separate species for ID purposes, or should we synonymize them for simplicities sake? That's the controversy, that's the fuckery. And this happens ALL THE DAMN TIME. For the purposes of this blog I am gonna go ahead and describe P. discordans as its own thing, but know that I know this is a tenuous position to take. This foliose lichen grows in closely appressed rosettes up to 10 cm across on siliceous rocks in costal and upland regions of Europe. It has angular, sublinear lobes with a dark brown upper surface lined with white pseudocyphellae. The lower surface is black with abundant, forked rhizines. It has cup-shaped, concolorous apothecia. And as noted earlier, P. discordans differs chemically as it produces protocetaric acid instead of salazinic acid as in P. omphalodes.

images: source | source

Parmelia sulcata

Photo credits: Jason Hollinger

First described as Parmelia cumberlandia. Also known as rockfrong lichen, supposedly, but I suspect that might be a typo.

The photobiont is the alga Trebouxia. Widespread, apparently, growing on acidic rock.

Parmelia sp

Carnaxide/Portugal (3/03/2024)

Parmelia submontana

This foliose lichen grows on trees in old, humid, boreal-montane forests in Europe, Africa, Macaronesia, and Asia. It is characterized but its geotropically oriented, pendulous lobes with an upper surface covered is long pseudocyphellae, punctiform soralia, and globose isidia. The lower surface is black , and has furcate, black rhizines. It only rarely produces apothecia. I have been on the lookout for this species in the German Alps for the last few years and have yet to find it, but I am sure I will someday. You can't evade me forever, P. submontana!

images: source | source | source

Parmelia pinnatifida